Friction brake



April is w24. l mmm@ G. 4.,..1s-MWH f A FRICTION BRA-KE Filed Apr-5.1 11.. :ms 2- sneets-shee'c 1 e. L. SMITH 'Y FRICTION BRAKE 'med April 11 1923 2 shaun-shut 2 Apil 1s 1924.l

Ille

- locking Patented Apri-1.5 1924' z tisane rarer( Erica.

GEORGE'L. slgTiI, or WASHINGTON, nIsTnIcT or concurra, AssIGNoa To UNITED STATES- annuaires coMrANY, or WASHINGTON, DISTRICT or COLUMBIA, a con..v

Appiiuon sied apra-i1, 1923. 'semi no. 631,392.

'To all whom it may concern.' Be it known fthat I, GEORGE L. SMITH, a citiz -of the United States, a'nd resident of Wa gton, in the District of Columbia,

have'invented certain new and useful 1111-' provements in Friction Brakes, set forth 1n the annexed specication.

My invention relates to friction brakes operable in pairs or multiples of pairs, such l i0 as those usually fitted to the wheels of motor vehicles,.and constitutes further develop-l 'ment of the mechanism described in my- Letters Patent No. 1,440,842 of January 2, 1923. f f

More particularly the invention of my resent 'application relates to mechanism or equalizing the braking force exerted by @uplicate brakes arranged' for application' .to retard either of two opposite rotary movement-s, and-including therein means for said mechanism inoperative when the brakes' are applied toretard one of said -movements Furthermore, my present in- -vention embodies means for .maintaining the operation of said mechanism e'ective to equalize said braking eii`eet,'irre spectiveof the'wear of the brakes, and such other novelty in detailconstruction as is essential-to attainthe main purposes of the inventio'n.

L I will describe my invention as applied to an external .contracting brake system as such a system is Well known and easily understood, and in addition, I will indicate brieliy its application to an internal expand brake system,A l

Inutle drawings illustrating my invention- Y Figure 1 is a rear view of a rearaxle 40 of an ,automobile equipped with my invention with parts shown in inoperative position Y F igure 2,"a view similar to Figure 1 with parts shown in operative position 3 Figure 3, a partial view partly in section of the left brake viewed from the inside with parts shown in inoperative position,

Figure 4, a view similar to'Figure 3 with the parts shown in full and dotted lines in the positions they would occupy under certain conditions of operation.

'Figure 5, a fr a 0 oa conventional rake operating means in association with the brakes.

ental perspective view .'Fig. ,6, a section on the line' 6-6 of Fig. 4.

In the drawing A represents -the rear axle of a motor vehicle, l, 1 the-brake drums, 2,- 2 the contracting brake bandssurrounding tliese drums, 3, 3, the brakeanchor studs, 4, 4 the brackets secured to a iionf rotating lpart of the axle andA carrying' the pivot pins 5, 5, upon which are mounted the bell-cranks 6, 6, all as previously described in my Letters Patent No. 1,440,842 of January 2,1923. y

connect the vertical arms of the bellcranks 6, by a connectingfrod 7 (hereafter called the equalizer rod) and latches 21, 2 1 pivoted -to respective. ends of the equalizer rod. Latch toes 23y are provided cured to the latches' 21 and to a fixed point above them, so that the latches normally engage the toes 23 and serve to lock the equalizer rod in its central position when the brakes are in inoperative position.

It will also be noted that these latches lock Vthe equalizer rod in its central position when the brakes are applied in backin the vehicle. In this case the eii'ectof the raking action is to rotate the bands rearwardly producing a downward force on the short arm of thel bell-cranks and an inward force on the long arms which is manifestly reon the brackets 4, 4 and springs 22 are sesisted by the latches. This locking action is provided to ensure eiiicient action of the brakes when applied to retardl rearward l :notion of a vehicle.

In retarding forward movement, the action 'of equalization, as described in the aforementioned Letters Patent, is not interfered with, as the equalizer rod and latches assume the position shown in Fig. 2, since the tension on this rod causes Vthe pivots het-Ween rod and latches to swing upward into alinement with the .pivots between the bell-cranks and latches, thus unlatching the latter and permittinfr free movement of the equalizer rod, in either di-I rection. -l

- The upper edges of the latch faces. are beveled as shown at 21?, so that the springs -22 will assist in returning the equalizer rod and the bellcranks to their central position and it will also be noted that the springs 22 pull inwardly and of themselves tend to return the equalizer rod to its central posiand' supporting mechanism is shown.

e pivot 51 -connects the brake-rod clevis 36 with the-` lever 38 and the retracting bolt V31. This bolt has a conical portion 32 under the head 33 which seats ina conical hole in the flange of the bracket 29 which is secured to the axle disk 55. The retracting s ring 35 secured in compression on the bo t 3l bythe collar 34 kee the bolt secure in. the conical seat ofthe ange 30, while the rear face of brake lining.

the head 33 seats a ainst the front face l.of

the llange, so that t e' pivot 51 is held fixed against upward or downward movement as long as the brake is released.. The lever 38 connects tothe togvle lever 39 at the 'pivot' 41 and it is scent 'at the front portion of the brake band and the parts 39, 43; 44 and 45 are thus suspended by the lever 38 yfrom the pivot 51.

In a plying the brake a forward pull'is exerte on'tlie rod,37 by pressing:` pedal 'D and the bolt 31 is ulled forward out of the conical seat, so t at the pivot -51 is -free to move up or down as the band 2 rotates to eect equalization 'as described in" my aforementioned Letters Patent and when the forward pull on the rQd 37 is released, itis also manifest that the spring,r 35 will cause the parts to-return to their initial position,`

thus effecting the necessary return rotary movement of theband 2, so that the latches 21 assisted by the springs 22 will engage their toes 23 and lockgthe equalizing rod in its'central position. The band l2 is therefore held free of the drum 1 by the proper positioning of the anchor stud 3 at the rear and the pivot 41 at the front, these pivots remaining fixed regardless of wear of the My self-adjusting mechanism which also acts as a self-regulating mechanism illustrated in Figures 3 and 4 and consists of the following parts The toggle lever 39 is constructed with a ratchet arm '53 held by a ratchet 54 on the lever 38, so that the band can be tightened b v a forward movement of this ratchet arm. This movement takes place around the pivot 41 and the `with duplicate brakes for retarding rotary pivots 40 and 42 areso positioned that an equal amount of take up willbe obtained for both the u per and lower halves'oxf the band 2. A lin 47 is pivoted to the arm 53 at tliepoint 57 and has a slot 48 in its` opposite end in which' pivot 52 on the lever 49 travels. The pivot 50 secures the lever 49 .to the disk'55 and said lever includes means 51' coacting with the disk to resist rotative force exerted by' the retracting' spring 35, said means, however, permitting rotative moveinent'of the lever under the inuence of a force exerted bythe driver inV is rotated forward, and as applying the brakes Now it will be evident that the pivot 51 will be pulled forward in applying the brakes `until the band `2 comes into contact with the drinn 1' and that 'the link 47 will be pulled forward-with the toggle lever 39 until. the end, 56 of the slot '48.reache's the'pivot 52 after which any furthe-r movement will cause a rotation of theleveri49 around its pivot 50. When the brake is released the' retracting'spring`35 'will vret-urn the various ports to their. .initial osition. The rearwardl movement of the.

until the limit of adjustmentof lever 'isi reached.

will be rotated rearwardly to produce egual- -By reference to Fiu're A4 it 'vv/ill' be seen,

ization'. This rotation is shown nsfraising the' pivot 41 =to the'position liggend the pivot. 51 is shown pulled forward and ihovd upward. .The position of the parts'j4tl,"47

and 53 shown in dotted lines is, the po itioncorresponding to no rotation of 'thee and, while those parts-in full lines are shown to correspond to'thc rotation above described.

It is seen that the pivot 57 moves upto the ,position 57 an'd that the distance .52-57 is greater thanV the distance 52-f57." To make up for this increase in distance, the lever 49 reviously described, this rotation will pro nce, when the brake' is released, a take up movement on the ratchet armand the band will be tightened. On the ,o posite brake. however, the'. reverse actiontak'ies place and the distance 52-57 becomes shortened. sol that no take up action occurs.-

I claim: l l l 1,-In abrake.4 system, the combination llO movements in either of two directions, of a brake equalizingdevice, and means lock- 'are applied to retard rotary movement in one of said directions.

.' 2. In a' brake system, -the combination 12o -ing said device inoperative when the brakes ferftive to lock said 3. In a brake system, the combination with duplicate brakes, of equalizing mechanism for the brakes, and a latch device ef- 'mechanism inoperative when thil brakes tary movement in one direction.

4. In va brake system, the combination with duplicate brakes, of equalizing mechanism for-tbc brakes, and a latch device effective to lock saidmechanism inop'rative when the brakes are applied to retard rotary movement,` in one direction, and ineffective to lock said mechanism inoperative nism for the brakes, and a when the brakes are applied to retard oppositif rotary movement.

In a brake system, the combination with duplicate brakes; of equalizing mechalatch devi normally positioned to lock said against operative movement, and actuated to release position by movement of brakes.

6. In abrake system, the combination are applied to retard `ro` with duplicate brakes, mechanism' the mecha-.- nism resulting from application pf thesignature.`

plying device, and a brake emlalizing mech-4 anism connecting the brakes, of retracting means for 'the device and brakes ing to support the brakes when the latte are in Y movement when the brakes are applied andv against such movements when the serving to support. the brakes when the latter are in retracted i locked brakes are retracted and position.

8. In a brake system,

of mechanism for equalizing 'the braking effect of the brakes, and automatic means for maintaining the operation of 'said mechanism effective to the combination equalize ,said braking effect irrespective of the wear of said brakes.

In testimony whereof lI hereunto aix my GEoRGE LL Smm.' 

